Polarization-Inverted Growth of ScAlN Thin Film by Si doping

Polarization-inverted multilayer structures are important for high frequency and high power operation of BAW devices. There are many ways to control the polarization of AlN, one of which is Si doping. In this study, inspired by the previously reported N-polarity growth of SiAlN, we considered that ScAlN thin films can also be grown N-polar by doping Si, and SiScAlN thin films were fabricated. As a result, N-polarized epitaxial SiScAlN thin films were obtained. Furthermore, we estimated the electromechanical coupling coefficient of SiScAlN thin film and compared it with SiAlN thin film.